Avandia and metformin in one pill allowing for smaller TZD dose GlaxoSmithKline hopes to launch its new combination product for treating diabetes by the end of 2002, the company states. The new product combines Avandia(R) (rosiglitazone), a member of the thiazolidinedione class of drugs, and metformin, marketed by Bristol-Myers Squibb as Glucophage(R).

Avandia has already been approved by the Food and Drug Administration for treating type 2 diabetes both as a single therapy and in combination with metformin.

The class of drugs know as thiazolidinediones (TZDs) was tarnished in 2000 when Rezulin (troglitazone) was withdrawn from the market because of liver toxicity. According to GSK’s CEO, J.P. Garner, the new Avandia/metformin combination will help restore trust in TZDs because it allows smaller doses of the TZD.

But Avandia faces a new safety question: whether the product is safe to use for patients taking insulin. In February 2001, the FDA added warning statements to the Avandia label regarding kidney and cardiovascular side effects, but deemed an Avandia/insulin combination "approvable." Revised labeling, however, includes a bolded statement that "the use of Avandia in combination with insulin is not indicated."

The FDA issued a warning letter to GSK in June 2001 for including conflicting messages regarding Avandia’s use with insulin. Following a "Dear Doctor" letter emphasizing the safety issues, off-label use of Avandia in combination with insulin fell from about 10 percent to 2 percent, according to GSK Chief Operating Officer Bob Ingram.